The present invention is directed to 2,3-difluoro-5-(trifluoromethyl)pyridine and to methods of preparing and using the same.
Pyridyloxyphenoxy alkanoic acids and their derivatives are known herbicidal agents. 2-(4-((3-Chloro-5-(trifluoromethyl)-2-pyridinyl)oxy)phenoxy)propanoic acid and derivatives and 2-(4-((5-(trifluoromethyl)-2-pyridinyl)oxy)phenoxy)propanoic acid and derivatives are promising herbicides in the developmental stages of commercialization. In copending application Ser. No. 389,840 filed June 18, 1982, it is shown that pyridyloxy phenoxy alkanoic acids having a fluoro in the 3 position of the pyridine ring have unexpectedly superior herbicidal activity. The present compound, i.e., 2,3-difluoro-5-(trifluoromethyl)pyridine, is a valuable chemical intermediate which can be used in preparing 2-(4-((3-fluoro-5-(trifluoromethyl)-2-pyridinyl)oxy)phenoxy)alkanoic acids and derivatives thereof.
The process of the present invention is an improved method of preparing an intermediate employed in preparing 2-(4-((3-fluoro-5-(trifluoromethyl)-2-pyridinyl)oxy)phenoxy)alkanoic acids and derivatives thereof which requires fewer process steps than those disclosed in copending application Ser. No. 389,840 filed June 18, 1982. Additionally, the compound of the present invention, provides an intermediate which reacts more readily with 2-(4-hydroxyphenoxy)propionic acid and derivatives thereof, resulting in a higher yield of end product when compared to intermediates containing chloro or bromo in the 2 position of the pyridine ring.